Hybrid Au/CuO Nanoparticles: Effect of Structural Features for Selective Benzyl Alcohol Oxidation

Abstract

Hybrid Au/CuO NPs supported on carbon (Vulcan-XC72) with different Au/Cu molar ratios (i.e., 13/1, 4/1, 1/1, and 1/ 17) were synthesized by the solvated metal atom dispersion approach. High-resolution transmission electron microscopy, scanning transmission electron microscopy−electron energy loss spectroscopy maps, and extended X-ray absorption fine structure measurements showed the presence of a Au/CuO core−shell heterostructure having narrow size distributions (mean diameter < 4.7 nm) regardless of their composition. The role of their structure and composition was evaluated for catalytic liquid-phase selective benzyl alcohol oxidation with respect to their monometallic counterparts. As a result, a strong synergistic effect of Au/ CuO heterostructures was revealed, which is strictly dependent on the CuO coverage degree of the Au-rich core and thus to the Au/Cu molar ratio. Highest catalytic activity was observed when the CuO shell only partially covers the Au−NP surface (i.e., at high Au/Cu molar ratios: 13/1, 4/1). On the other hand, at high Cu loadings (i.e., Au/Cu molar ratios: 1/1 and 1/17), the CuO shell wraps the Au core completely, inhibiting the catalytic activity.

Bimetallic gold and palladium nanoparticles supported on copper oxide nanorods for enhanced H2O2 catalytic reduction and sensing

“…The morphology and structural properties were studied to understand the synergistic effect between metallic systems. 25 …”

“…The morphology and structural properties were studied to understand the synergistic effect between metallic systems. 25 X-ray diffraction (XRD) was used to analyse the successful formation of CuONRs and mono and bimetallic gold and palladium nanoparticles supported on CuONRs. Fig.…”

Finely Iron-Dispersed Particles on β Zeolite from Solvated Iron Atoms: Promising Catalysts for NH3-SCO

“…Pd, Pt, Au) [41][42][43] and non-noble (e.g. Cu), 44,45 metal nanoparticles, named solvated metal atoms, which can be easily immobilized onto different kind of supports guarantying a high dispersion of the metal phase. In order to unravel interesting relation between aggregation state of the metal phase and the corresponding catalytic performances, low concentration (ca.…”

Benzyl alcohol to benzaldehyde oxidation on MnOx clusters: Unraveling atomistic features

“…In this respect, although supported noble-metal catalysts (e.g. Au, Pt, Pd) exhibit good performance under mild reaction conditions [7][8][9][10][11][12][13][14][15], high costs and deactivation phenomena, due to overoxidation and/or fouling of active sites, are severe drawbacks for their industrial exploitation [16,17].…”